\section{Introduction}
\label{section:introduction}

{\bf Levi redrafts and then Michalis does}


General Motors (GM) is a big automotive company that uses a lot of software for
its cars.
Currently GM is going through the process of migrating models in its proprietary
language called Vehicle Control Software (VCS) 
 to
AUTOSAR.
GM uses product lines extensively.
Thus GM is faced with the problem of migrating an entire product line of VCS
models to a new product line of AUTOSAR models.
GMers thus need to create expensive, purpose-specific migration
transformations.
However, the state of practice does not facilitate doing this on the grand
scale. 
There is a lot of
inherent complexity in existing product lines.  This is true not only about
relationships between products but also a variety of properties that must be 
established between the input and output models.

% NOTE:
% Ideally, we are talking about properties like controlability, being within a
% particular scope, parameters being within particular characteristic...  I.e.,
% ideally, whatever properties GMers care about We don't know yet how to establish
% this, but this is the outline of the idealized paper.

The task of a product-line level transformation is therefore not only to
maintain relationships between the features and relationships between the
products but also to make sure that the transformation maintains certain
properties, expressed in terms of pre- and post- conditions.
%{\bf MF: I am not sure where else to add a place-holder about properties.}

In order to do this we are going to take a transformation tool (DSLTrans) that
allows us to determine that individual transformations maintain such desired
properties and can effectively transform models of GM-size.  We are going to
create lifting of DSLTrans and then apply it to these taks and then do lessons
learned.

In the following we report our experience from lifting the VCS-to-Autosar
transformation and applying it in the GM context. There are two main categories
of lessons learned:
\begin{enumerate}
\item Lessons learned about the experience of lifting
\item Lessons learned about applying the transformation to the GM product line
\end{enumerate}
